• A radioactive contamination scandal in Banten, Indonesia, has left local workers like Sakinah and Roni jobless and exposed to health risks after Cesium-137 was traced to factories in the Modern Cikande Industrial Estate.
• Government investigations revealed widespread contamination across 22 companies, prompting cleanup operations and health checks for more than 1,500 residents living near the exposure zone.
• Authorities have struggled to find secure storage for the contaminated materials while admitting regulatory lapses that allowed radioactive scrap metal to enter the country unchecked.
• Experts and environmental groups are now urging tighter import controls, improved radioactive waste management and stronger coordination among ministries to prevent another silent disaster.

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BANTEN, Indonesia — The rain had just passed over Nambo Udik, a village in Cikande, Serang, Banten. The air hung heavy and damp, and puddles lingered in the muddy yard in front of Sakinah and Roni’s home.

These days, the couple spends most of their time indoors, gazing out at the quiet street. It has been more than a month since they last worked after news broke of radioactive contamination in the Modern Cikande Industrial Estate.

Sakinah lost her job when PT Bahari Makmur Sejati (BMS Foods), her employer, abruptly shut down. The closure followed an alarming report from the U.S. Food and Drug Administration (FDA) on Aug. 19, which detected traces of radioactive material in a frozen shrimp shipment from Indonesia. The contaminated batch was traced back to BMS.

Government agencies — including the Ministry of Environment, the Nuclear Energy Regulatory Agency (Bapeten), the National Research and Innovation Agency (BRIN) and the police bomb squad Gegana — launched an investigation to uncover the radiation source.

What they found led back to PT Metal Technology (PMT), a metal smelting plant in the same industrial zone. There, Roni had worked as a helper for more than 10 years. Tests revealed that the radiation came from Cesium-137, a hazardous isotope commonly associated with nuclear waste.

By mid-September, both Roni and Sakinah had undergone medical examinations. Blood tests confirmed they had been exposed to radiation. Roni was prescribed Radiogardase, which is designed to flush Cesium-137 from the body. He takes nine of them a day, three at a time, from a box of 63 tablets. Sakinah wasn’t as lucky. At her former workplace, the medical checkups were cursory: a brief examination, and little more.

“I wasn’t given medicine like my husband, just vitamins. Now the vitamins are finished,” she said.

Roni was prescribed Radiogardase, which is designed to flush Cesium-137 from the body. Image by Anggita Raissa/Mongabay-Indonesia.
Waste from factories near residential areas in Cikande was found to contain radioactive contamination. Image courtesy of Indonesian Ministry of Environment.

A wider trail of contamination

Both PT Metal Technology (PMT) and PT Bahari Makmur Sejati have since stopped operations. For hundreds of workers like Sakinah and Roni, the shutdown meant an abrupt end to their livelihoods, without a single rupiah in severance pay.

The Ministry of Environment later revealed that the problem was far more widespread than initially feared. Traces of Cesium-137 were found in 22 companies across the Modern Cikande Industrial Estate, with 10 contaminated points identified in scrapyards and vacant lots. The highest radiation readings came from PMT itself, ranging between 0.3 and 0.5 microsieverts per hour — 3-5 times higher than the safe threshold of 0.1 microsievert.

The contamination trail had, in fact, surfaced abroad. The U.S. FDA’s laboratory tests on frozen shrimp exported from BMS Foods detected Cesium-137 levels of nearly 68.5 becquerels per kilogram — still below the danger threshold of 1,200 Bq/kg, but enough to trigger alarm.

Experts stressed that such contamination poses no immediate health threat. Yet, prolonged exposure to Cesium-137, even at low levels, can quietly increase the risk of cancer and other long-term diseases.

Cesium-137 is a human-made radioactive element, a byproduct of nuclear reactors, often used in industry and research for density measurement and other applications involving nuclear energy. When improperly handled, however, it can escape into the environment — and once it does, it doesn’t stay put.

The radiation from Cs-137 is classified as ionizing radiation, according to Ishak, head of the legal, cooperation, and public communication bureau at Bapeten. It’s the type that can alter the structure of living cells, he said.

He described two types of health effects linked to radiation exposure. Deterministic effects occur when radiation doses exceed a threshold, producing visible biological damage, such as skin reddening. Stochastic effects, by contrast, have no minimum threshold and can occur even at very low doses, increasing the long-term probability of developing cancer.

Cesium-137 also spreads easily through the environment, Ishak noted. It dissolves in water, allowing contamination to flow into rivers, lakes and seas. It can be absorbed by plants, enter the food chain or bind to soil particles — particularly in clay-rich agricultural land. In this way, contamination doesn’t stay confined to the site, Ishak said.

He added the contamination moves, it persists and it can eventually reach humans, whether through direct exposure or through consumed foods. Inside the human body, Cs-137 tends to accumulate in soft tissues, especially muscles, where it emits beta and gamma radiation that can damage nearby organs over time.

Indonesia’s radiation safety standards are governed by several regulations, including Bapeten Regulation No. 4/2013 on Radiation Safety in the Use of Nuclear Energy and the Ministry of Health Regulation No. 1031/2011, which sets the maximum allowable radioactive contamination levels in food.

The Cs-137 task force installed a yellow line to mark areas for upcoming decontamination. Image by Anggita Raissa/Mongabay-Indonesia.

Containment and uncertainty

In the weeks following the discovery of Cesium-137 contamination in Cikande, a joint government task force, including the Ministry of Health, began screening local residents and industrial workers. A total of 1,562 people underwent medical checks.

For the people of Nambo Udik village, which sits less than 100 meters (330 feet) from the contaminated metal plant, anxiety runs deep. Living within the exposure radius has left villagers worried about what they can’t see, like the long-term effects on their health, their soil and the water they depend on.

From the screenings, nine individuals were confirmed to have been exposed to the radioactive isotope. Each underwent whole-body counting (WBC) tests and received medication from the Cikande community health center.

On Oct. 7, Environment Minister Hanif Faisol Nurofiq met with residents from three affected villages — Barengkok, Sukatani and Nambo Udik — to address the growing concern. Community leaders and local neighborhood heads gathered to hear the government’s plan.

Hanif assured them that all radioactive metal materials would be secured inside the PMT building, serving as a temporary holding site before being moved to a permanent storage facility. He promised the transfer process would be completed quickly and according to strict safety protocols.

“The entire operation will be closely monitored by Bapeten to ensure no additional risk to the community or the environment,” he said, adding that the government would coordinate across ministries to find a safe long-term site that meets international standards.

At the operational level, cleanup efforts are being led by BRIN. Maman Kartaman, who heads BRIN’s Center for Nuclear Materials and Radioactive Waste Technology, said the removal of contaminated materials would proceed in stages.

“From the first site, we managed to collect around seven quintals of metal contaminated with Cs-137,” Maman said. “Radiation levels there have now fallen from 1,200 microsieverts per hour to below 1 microsievert.”

During a site visit by Mongabay Indonesia, workers in full protective suits were seen loading 1-m (3-ft) metal drums filled with Cs-137-contaminated scrap onto the Police Mobile Brigade’s specialized chemical, biological and radioactive transport vehicles.

Yet even as cleanup advances, the question of where to store the radioactive waste looms large.

Ishak, the spokesperson for Bapeten, acknowledged that Indonesia still lacks a proper medium- or long-term facility for radioactive material. “The volume of contaminated material is significant,” he told Mongabay Indonesia. “We need a secure and representative space large enough to contain it, and that’s not easy to find.”

Any storage site, he said, must be able to completely isolate radioactive material, preventing even the slightest chance of contamination spreading beyond its walls.

“The possibility of wider contamination must be entirely avoided,” Ishak said. “The facility must be capable of containing both radiation and the movement of contaminated material, so nothing escapes into the surrounding environment.”

The handling of metal waste contaminated with Cesium-137 radiation is being carried out by the Ministry of Environment in coordination with the Indonesian Police’s Mobile Brigade. Image courtesy of Indonesian Ministry of Environment.

Oversight failure and the scrap metal loophole

In what officials now admit was a serious oversight, the Indonesian government failed to detect radioactive contamination entering the country through imported scrap metal — a lapse that potentially led to the Cesium-137 leak in the Modern Cikande Industrial Estate. In response, authorities have temporarily frozen all import permits for used iron and steel.

“We must admit there was a gap in our monitoring system,” said minister Hanif, who also heads the Environmental Control Agency. “Perhaps we never imagined that radionuclides could reach Indonesia, but in reality, they managed to slip in through scrap metal.”

Speaking to Mongabay Indonesia in Serang on Oct. 7, Hanif said investigators have yet to confirm whether the Cesium-137 originated from imported metal scraps or from improperly disposed industrial equipment that contained radioactive materials.

To prevent a repeat, the government has ordered all industrial operators to install radiation portal monitors — scanners capable of detecting radioactive particles in imported materials — and to update their inspection systems. “Only when these two measures are fulfilled, will import permits be reissued,” Hanif said.

For years, Indonesia’s waste management policies have focused mainly on hazardous and toxic materials, known as B3 waste. But as Hanif said, little attention has been given to the possibility of radioactive waste entering through international scrap metal trade routes.

Environmental experts say that blind spot is now exacting a heavy price.

“The government was clearly caught off guard, both in its monitoring and its regulatory framework,” said Yuyun Ismawati Drwiega, co-chair of the International Pollutants Elimination Network (IPEN). She criticized the use of the green lane system for scrap metal imports, which allows shipments to bypass thorough inspection. “Scrap metal should never enter through the green lane, even with recommendations from technical ministries,” she said.

A scrapyard containing iron materials contaminated with the radioactive substance Cesium-137 was discovered in the Modern Cikande Industrial Estate, Serang Regency, Banten. Image by Anggita Raissa/Mongabay-Indonesia.

Yuyun urged tighter import controls and clear limits on acceptable contaminant levels in scrap shipments. While she noted that international standards for radioactive waste management are extremely strict, making it unlikely the contamination came directly from imported metal, she called for a deeper domestic investigation to trace possible local sources.

Her concerns were echoed by Dwi Sawung of the Indonesian Forum for the Environment, WALHI. “If the Cesium-137 came from imported materials, it would expose a major failure in the government’s oversight of secondhand goods,” he said.

Dwi has long opposed Indonesia’s practice of importing used materials, from industrial slag and scrap metal to recycled paper and waste. He pointed to a previous case where imported paper waste turned out to contain mixed household garbage. “This happens because the government tolerates the import of nonhomogeneous raw materials, and that opens the door to dangerous substances.”

If radioactive materials are indeed slipping in through such loopholes, Dwi warned, the consequences could be far-reaching. Contamination could spread beyond industrial sites, even threatening food-processing industries that rely on nearby water sources and supply chains.

“To stop this from happening again, the government must ban all imports of used materials of unclear origin, in any form, unless they’re proven homogeneous and tightly inspected,” Dwi said.

Yuyun, meanwhile, called for a complete overhaul of Indonesia’s import monitoring system. She said all scrap metal imports should be processed under the red lane system, which mandates rigorous inspection. She also pushed for regulatory updates to define clear contamination thresholds, along with improved national capacity for managing radioactive waste, not just in industrial facilities, but also in hospitals and laboratories that use radioactive isotopes.

“Above all, we need better coordination among ministries. Overlapping authorities only weaken our defenses,” Yuyun said.

“If we don’t learn from this incident, radioactive hazards will remain an invisible threat, not just to the environment, but to every community that lives in its shadow,” she said.

The Indonesian government has declared the Cesium-137 radiation contamination in the Modern Cikande Industrial Estate, Serang, Banten, a “special incident.” The Environment Ministry plans to file both criminal and civil lawsuits against PMT, identified as the main source of contamination, and PT Modernland, the estate’s management company. Hanif said the lawsuits will target violations of environmental protection laws, though experts like Yuyun note that past corporate breaches often ended with light sanctions, allowing companies to evade accountability.

For now, the waste remains at PMT — a temporary fix for a problem that could persist for decades. In Nambo Udik, where the wind still blows across empty factory yards, residents wait for more than reassurance. They want to know that the danger has truly passed — and that their village won’t remain a silent repository of someone else’s negligence.

Residents like Sakinah and Roni are bearing multiple burdens. They face the threat of radiation exposure, the loss of their jobs and uncertainty about their future as recovery efforts continue.

“I just hope there will be special attention for us. We are victims, workers directly affected by this. We need food, and my child is still in school,” Sakinah said.

Workers walk past a scrapyard contaminated with the radioactive substance Cesium-137 in the Modern Cikande Industrial Estate, Serang Regency, Banten. Image by Anggita Raissa/Mongabay-Indonesia.

This story was first published here, here, here, here, here and here on Aug. 26, Sep. 13 and 24, Oct. 2, 8, and 14, 2025.

Basten Gokkon, senior staff writer for Indonesia at Mongabay, adapted this reporting. Find him on 𝕏 @bgokkon.

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